6.1 Acids and Bases
SNC2D
Properties of Acids
Acids:
 taste sour
Properties of Acids
Acids:
 taste sour
 are corrosive
(react with metals to produce hydrogen gas)
Properties of Acids
Acids:
 taste sour
 are corrosive
(react with metals to produce hydrogen gas)
 release hydrogen ions (H+) in solution
(therefore, the physical state is always aqueous)
Examples of Acids

acetic acid
HC2H3O2 (aq)
Examples of Acids

acetic acid (in vinegar)
HC2H3O2 (aq)
Examples of Acids


acetic acid (in vinegar)
HC2H3O2 (aq)
citric acid (in citrus fruit)
H3C6H5O7 (aq)
Examples of Acids



acetic acid (in vinegar)
HC2H3O2 (aq)
citric acid (in citrus fruit)
H3C6H5O7 (aq)
carbonic acid
H2CO3 (aq)
Examples of Acids



acetic acid (in vinegar)
HC2H3O2 (aq)
citric acid (in citrus fruit)
H3C6H5O7 (aq)
carbonic acid (in soft drinks)
H2CO3 (aq)
Examples of Acids




acetic acid (in vinegar)
HC2H3O2 (aq)
citric acid (in citrus fruit)
H3C6H5O7 (aq)
carbonic acid (in soft drinks)
H2CO3 (aq)
hydrochloric acid
HCl (aq)
Examples of Acids




acetic acid (in vinegar)
HC2H3O2 (aq)
citric acid (in citrus fruit)
H3C6H5O7 (aq)
carbonic acid (in soft drinks)
H2CO3 (aq)
hydrochloric acid (in your digestive system)
HCl (aq)
Naming Acids
Binary acids (hydrogen + a single element) are
called hydro_______ic acids
e.g. H2S(aq) is hydrosulphuric acid
Naming Acids
Oxyacids (hydrogen + a polyatomic ion) are
called:
_______ic acids if the name of the ion ends in -ate
_____ous acids if the name of the ion ends in –ite
e.g. HNO3(aq) is nitric acid (NO3- is nitrate)
HNO2(aq) is nitrous acid (NO2- is nitrite)
Writing Chemical Formulas
The following steps should be followed when writing acid
formulas.
1. Determine whether it is a binary acid or an oxyacid. If
it is a binary acid, the name starts with hydro- . If it is a
oxyacid, the name doesn’t start with hydro-.
2. Find the ion symbols and their charges using a periodic
table and then cross over the charges.
 If the oxyacid ends with -ic, the polyatomic ion’s
name must end with -ate.
 If the oxyacid ends with –ous, the polyatomic ion’s
name must end with –ite.
Writing Chemical Formulas
1. phosphoric acid
a.
does not start with hydro- , so it is an oxyacid
b.
look for the polyatomic that ends in –ate, since the acid
name ends in –ic (phosphate)
c.
cross over the charges, H+ PO43-
H3PO4 (aq)
2. hydrobromic acid
a. starts with hydro- , so it is a binary acid
b. look for the symbol and charges in the periodic table
c. cross over the charges, H+ BrHBr (aq)
Properties of Bases
Bases:
 taste bitter
Properties of Bases
Bases:
 taste bitter
 feel slippery
Properties of Bases
Bases:
 taste bitter
 feel slippery
 are corrosive (break down proteins)
Properties of Bases
Bases:
 taste bitter
 feel slippery
 are corrosive (break down proteins)
 release hydroxide ions (OH-) in solution
Examples of Bases



Sodium hydroxide NaOH
Calcium hydroxide Ca(OH)2
Aluminum hydroxide Al(OH)3
Examples of Bases
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



Sodium hydroxide NaOH
Calcium hydroxide Ca(OH)2
Aluminum hydroxide Al(OH)3
Sodium bicarbonate NaHCO3
Ammonia NH3
Writing Formulas for Bases
The following steps should be followed when writing base
formulas.
1. Use the periodic table and table of polyatomic ions to
identify the symbols for the cation and anion in the base
and their charges.
2. Cross over the charges.
e.g. : magnesium hydroxide
Mg2+
OH-
Mg(OH)2
Copyright © 2010 McGraw-Hill Ryerson Ltd.
Strong and Weak
Some acids and bases are much stronger (have a
higher concentration of ions in solution) than
others.
e.g. nitric acid is a strong acid;
ammonia is a weak base